Shoe with an energized quarter portion

ABSTRACT

A shoe with a quarter portion, having an upper, a sole, and a midsole, which further includes a pair of rigid rod-like elements which are coupled rigidly to the sole and/or midsole. The shoe further includes a pair of longitudinally extended flexing springs which are deformable and elastic around the axis of the malleolus of a user who wears the shoe. The flexing springs are adapted to accumulate and return elastic mechanical energy and are integral with the pair of rigid rod-like elements. The shoe further includes a quarter portion assembly that is associated with the pair of flexing springs and is adapted to make contact with a front tibial portion and two lateral portions of the leg of the user.

TECHNICAL FIELD

The present disclosure relates to a shoe with quarter portion that isparticularly but not exclusively useful and practical for theaugmentation and stabilization of the foot-leg joint of the human body,particularly of the ankle.

In general, the shoe with quarter portion according to the disclosurecan be used in various situations of motion or rest in which, due to animbalance of the center of gravity of the human body and/or angularvariations at the joint of the upper part of the leg, i.e., at thepelvis, and between the upper part and the lower part of the leg, i.e.,at the knee, and due to the consequent angular variations between thelower part of the leg and the foot, the resting of the weight force ofthe human body, through the foot, changes its distribution with anincrease in load on the metatarsal arch.

It should be noted, for example, that in the perfectly upright postureof is the human body the distribution of the resting of the weight forcethrough the foot can be approximated as ⅓ on the metatarsal arch and ⅔on the heel.

In greater detail, the disclosure relates to a shoe with quarter portionapplied to the lower part of the lower limbs of the human body, in orderto improve substantially its efficiency, understood as a ratio betweenthe mechanical work performed and the energy supplied to a system,during the execution of movements, such as for example walking, running,jumping, pedaling, skiing, skating, riding on level or ascending ordescending terrains but also during the execution of static actions.

The latter can be identified for example as the posture of sitting, oras the actions related to control of the position of the human body,such as for example driving a motorcycle, hitting a target with aweapon, working while forced to a continuous upright position or, moregenerally, in conditions that require an imposed posture.

Moreover and in particular, the shoe according to the disclosure isuseful and practical for the execution of all the typical activities ofwalking and of states related to a non-horizontal position of the humanbody in which the weight force is rested through one or both feet.

BACKGROUND

Some conventional types of shoe assist and support the movements of thelower parts of the leg and of the foot.

These conventional shoes, such as those of the sports type, for exampleparticular types of shoes or equipment for specialized use, such as skiboots, trekking boots, skating boots, and others according to the priorart, are proposed generally for control by a specific motor state andare mostly of the protective or imposed-position type.

Also as regards known systems studied for dynamic states, the use ofmechanical systems for the accumulation and return of energy in theprior art is reserved to certain categories of springs, both tractionsprings and flexing springs, characterized by materials the elasticresponse of which differs significantly from the natural muscular one,requiring for their operation mechanical control elements, such as forexample friction elements, which are sophisticated and scarcely reliableas well as difficult to learn.

In devices of the known type, therefore, no characteristic that differsfrom a specialized shoe is found, and in view of this, and besides anyperformance improvement, they do not influence in any manner, or in ascarcely relevant manner, the efficiency of the human body as describedabove.

U.S. Pat. No. 2,567,195 disclosed an orthopedic brace for treatingdrop-foot, constituted substantially by a shoe and a mechanicalstructure which are mutually coupled and are to be arranged on the lowerlimb of a user. In particular, the mechanical structure comprises aplanar joint, arranged at the ankle of the user and adjusted by ahelical tension spring.

SUMMARY

The aim of the present disclosure is to overcome the limitations of theprior art that have been described above, by devising a shoe forsupporting walking that allows to achieve both better effects, in termsof efficiency, weight and energy consumption, than those obtainable withdevices of the known type, be they of the “active” or “passive” type,and better effects, in terms of comfort and performance, with respect tothe various types of conventional shoe.

This is achieved by allowing to control angular foot-leg movementsduring static or dynamic rotation of the ankle about the malleolus, bymeans of the activation, assigned exclusively to the weight force, ofelastic elements characterized by a response that is very close to thenatural muscular law of elasticity.

Within this aim, the present disclosure conceives a shoe for supportingwalking that offers a high level of comfort to the user who uses it,both during use and when putting it on, characterized therefore by areduced weight, easy accessibility and fit, and by an optimumdistribution of the pressure that is is generated between the shoeitself and the leg of the user during use.

The present disclosure devises a shoe for supporting walking that can beprovided by using materials that are commonly used and productionprocesses which are relatively simple or in any case not excessivelysophisticated.

The present disclosure further conceives a shoe for supporting walkingthat can be used in various fields, states of motion and/or steps ofwalking and is not limited to a specific field, state of motion and/orstep of walking.

The present disclosure also devises a shoe for supporting walking thatallows to follow in the best possible way the movements of the leg ofthe user in its rotation about the malleolus, furthermore allowing toobtain a more natural and less imposed movement, particularly on unevenand/or not perfectly level ground.

The present disclosure provides a shoe that is highly reliable,relatively simple to provide, and at competitive costs if compared withthe prior art.

This aim, as well as these and other advantages which will become betterapparent hereinafter, are achieved by providing a shoe with quarterportion, comprising an upper, a sole and a midsole, wherein the shoecomprises a pair of rigid rod-like elements which are coupled rigidly tothe sole and/or midsole, a pair of longitudinally extended flexingsprings which are deformable and elastic around the axis of themalleolus of a user who wears the shoe, said flexing springs beingadapted to accumulate and return elastic mechanical energy and beingintegral with the pair of rigid rod-like elements, and a quarter portionassembly that is associated with the pair of flexing springs and isadapted to make contact with a front tibial portion and with two lateralportions of the leg, which are contiguous to it, of the user.

BRIEF DESCRIPTION OF THE DRAWINGS

Further characteristics and advantages of the disclosure will becomebetter apparent from the description of a preferred but not exclusiveembodiment of the shoe according to the disclosure, illustrated by wayof nonlimiting example with the aid of the accompanying drawings,wherein:

FIG. 1 is a perspective view of a first embodiment of the shoe withquarter portion, according to the present disclosure;

FIG. 2 is a lateral elevation view of the first embodiment of the shoewith quarter portion shown in FIG. 1, according to the presentdisclosure;

FIGS. 3 and 4 are lateral elevation views which show respectively twodifferent consecutive steps of the operation of the first embodiment ofthe shoe with quarter portion shown in FIG. 1, according to the presentdisclosure;

FIG. 5 is a perspective view of a second embodiment of the shoe withquarter portion, according to the present disclosure;

FIG. 6 is a lateral elevation view of the second embodiment of the shoewith quarter portion shown in FIG. 5, according to the presentdisclosure;

FIG. 7 is an exploded view of a portion, in particular a midsole, of thesecond embodiment of the shoe with quarter portion shown in FIG. 5,according to the present disclosure;

FIG. 8 is a sectional view of a portion, in particular a quarter portionassembly, of the second embodiment of the shoe with quarter portionshown in FIG. 5, according to the present disclosure; and

FIGS. 9 and 10 are sectional views of a portion, in particular a rigidrod-like element, of the second embodiment of the shoe with quarterportion shown in FIG. 5, according to the present disclosure.

DETAILED DESCRIPTION OF THE DRAWINGS

With reference to FIGS. 1-10, the shoe with quarter portion according tothe disclosure, designated generally by the reference numerals 10, 60,substantially comprises an upper 14, 64, a tongue 12, 62, a closuresystem 18, 68, a sole 16, 66 and a midsole 16A, 66A, the midsole 16A,66A being interposed between the upper 14, 64 and the sole 16, 66.

The shoe 10, 60 with quarter portion according to the disclosure furtheris comprises also a pair of rigid rod-like elements 22, 72 with asubstantially longitudinal extension which are integral with the soleand/or midsole 16A, 66A, a pair of flexing springs 24, 74 having asubstantially longitudinal extension which are integral with the pair ofrigid rod-like elements 22, 72, and a quarter portion assembly 32 and 82associated with the pair of flexing springs 24 and 74.

The upper 14, 64 and the tongue 12, 62 are typically made of leather orfabric. The closure system 18, 68 is typically provided by means oflaces, Velcro buckles, elasticized inserts. The sole 16, 66 is typicallymade of rubber and derivatives thereof or of natural leather. The insoleor midsole 16A, 66A is typically made of thermoplastic polymers orcomposite materials.

The rigid rod-like elements 22, 72 of the shoe 10, 60 with quarterportion according to the disclosure are coupled rigidly to the sole 16,66 and/or midsole 16A, 66A so as to form with them or with part of thema single body.

In one embodiment of the shoe 10, 60 with quarter portion according tothe disclosure, the rigid rod-like elements 22, 72 can be arranged andrigidly coupled to the sole 16, 66 and/or midsole 16A, 66A in a positionthat is comprised between the outer end of the heel and the region thatprecedes the resting of the metatarsus and of its natural joint.

In one embodiment of the shoe 10, 60 with quarter portion according tothe disclosure, the rigid rod-like elements 22, 72 can be mutuallycoupled rigidly by means of an additional rigid rod-like connectingelement 23, 73, which is arranged transversely with respect to theirlongitudinal axis and is coupled rigidly to the respective lower ends.

The rod-like elements 22, 72 are flexurally rigid along any plane;furthermore, the rod-like elements 22, 72 are also torsionally rigid.The rigid rod-like elements 22, 72 are provided with a geometry and bymeans of a material that can give them characteristics of flexural andtorsional inertia that are at least 5 times greater than those of theelastic elements 24, 74.

The rigid rod-like elements 22, 72 are inclined toward the rear portionof the shoe on a rotation axis that is perpendicular to the longitudinalaxis of the shoe 10, 60 with quarter portion, preferably with an anglecomprised between 90° and 160°.

In one embodiment of the shoe 10, 60 with quarter portion according tothe disclosure, the rigid rod-like elements 22, 72 comprise elements 20,70 for adjusting their inclination which are adapted to lock said rigidrod-like elements 22, 72, preventing their movement, in particularrotation. For example, the adjustment elements 20, 70 can be of thefriction type with screws, with a reversible ratchet, with a detent,with a friction clutch.

In an embodiment of the shoe 10, 60 with quarter portion according tothe disclosure, the inclination adjustment elements 70 comprise a firstblock part 92 and a second block part 93, each of which comprises a slotwhich is adapted to engage the rigid rod-like connecting element 73. Thefirst block part 92 is fixed to the midsole 66A. Once the rigid rod-likeconnecting element 73 has been positioned in the slots of the blockparts 92 and 93, said parts are coupled and fixed by means of a pair ofbolts, each of which comprises a screw 94 which is fixed to the midsole66A and a hexagonal threaded nut 95. Consequently, each one of the blockparts 92 and 93 comprises a pair of holes adapted for the passage of thescrews 94.

By acting on these adjustment elements 20, 70 it is possible to modifythe inclination of the pair of rigid rod-like elements 22, 72 andconsequently the angle formed by these rigid rod-like elements 22, 72with respect to the longitudinal axis of the shoe 10, 60 with quarterportion, so as to be able to vary the initial or stable geometricconfiguration of the flexing springs 24, 74.

In one embodiment of the shoe 10, 60 with quarter portion according tothe disclosure, the inclination of the rigid rod-like elements 22, 72can be chosen, at the design level, with a fixed angle that ischaracteristic for any user.

In one embodiment of the shoe 10, 60 with quarter portion according tothe disclosure, the rigid rod-like elements 22, 72 have a cross-sectionwhich is in any case closed, with any geometry, in addition to thecircular one that is shown.

The flexing springs 24, 74 are deformable and elastic about the virtualaxis of rotation of the malleolus of the user and are adapted toaccumulate and return elastic mechanical energy when they are deformedand released from the angular variations about the center of rotation ofthe malleolus proper induced by the resting loads on the plantar archduring the states of motion and/or rest, caused by the simple weightforce or by the voluntary muscular activation of the joint on the partof the user.

The flexing springs 24, 74, with respect to the deformation planedescribed above, are capable of deforming elastically in a certain andcontrolled manner, resuming, when the action applied to their endthrough the quarter portion assembly 32, 82 ceases, by virtue of theaccumulated elastic energy, its initial and/or stable geometric shape.

Even for very small angles of incidence between the foot and the legwhich are well beyond the natural possibilities of the joint beingconsidered, their deformation and the consequent stress is alwayscomprised within their elastic limit, being thus inherently “safe” asregards their state of failure.

The flexing springs 24, 74 have a substantially longitudinal extensionand can have a rectilinear shape or a shape that is curved on one ormore axes of curvature.

In one embodiment of the shoe 10, 60 with quarter portion according tothe disclosure, the flexing springs 24, 74 have a substantiallyrectangular cross-section and their thickness, for the optimization ofthe mechanical behavior (referred in particular to the functions of thestrength modulus and of the inertia modulus) is not greater than 2 mm.

The flexing springs 24, 74 are rigidly coupled to the respective rigidrod-like elements 22, 72 for example with an interlocking coupling. Inis particular, the lower end of a flexing spring 24, 74 is coupledrigidly to the upper end of a respective rigid rod-like element 22, 72and vice versa.

In one embodiment of the shoe 60 with quarter portion according to thedisclosure, the upper end of the rigid rod-like element 72 comprises acylindrical seat 102 and the lower end of the flexing spring 74comprises an insert 104. The insert 104 of the flexing spring 74 isinserted in the cylindrical seat 102 of the rigid rod-like element 72.The insert 104 is locked longitudinally in the cylindrical seat 102 bymeans of a locking screw 106 which is engaged in the insert 104 and acorresponding locking washer 106, which therefore prevent the exit orextraction of the insert 104 from the cylindrical seat 102.

Advantageously, the insert 104 is configured to rotate about thelongitudinal axis of the cylindrical seat 102, and consequently theflexing spring 74 can rotate about the longitudinal axis of the rigidrod-like element 72. The locking screw 106 also constitutes the strokelimiting block for the rotations of the insert 104 of the flexing spring74 in the cylindrical seat 102 of the rigid rod-like element 72.

In different embodiments of the shoe 10 with quarter portion accordingto the disclosure, the rigid coupling between the ends of a flexingspring 24 and of a rigid rod-like element 22 can be an interlockingcoupling defined by resins for adhesive bonding, co-molding ofthermoplastic or thermosetting resins, nuts, or other fixing elementscapable of ensuring transmission of the maximum rotational torque of theflexing spring 24, related to their preferential inward flexing plane,to the system represented by the sole-upper structure and consequently,with minimal dissipation, to the foot of the user. A rigid rod-likeelement 22, 72 and a flexing spring 24, 74, which are rigidly coupled,are substantially rectilinear and mutually parallel.

The flexing springs 24, 74 characterized by a rectangular cross-sectionand interlocked at their base to the rigid rod-like elements 22, 72 andconnected rotatably through the rigid upper terminals 26, 76 and thecoupling is elements with hinge-like retention 38 or the sphericaljoints 88, to the rigid support 34, 84 thus form along the plane that isperpendicular to their preferential flexing plane, a tip that issubstantially rigid and stable and is adapted to stabilize and protectlateral rotations of the ankle, by virtue of the lateral contactportions of the leg that are contiguous to the tibial resting of thequarter portion assembly 32, 82.

It should be noted that in order to ensure user safety, the placementand the inclination of the rigid rod-like elements 22, 72 with respectto the shoe 10, 60 with quarter portion and the shape of the flexingsprings 24, 74, must be such as to maintain the flexing arch of theflexing springs 24, 74 in every step of foot-leg flexing in a rearposition, i.e., behind the malleolus of the user.

The upper end of a flexing element 24 comprises a rigid terminal 26, 76.This rigid upper terminal 26, 76 is generally made of thermoplastic orthermosetting material and is connected rigidly to the elastic elements24, 74 by means of co-molding, adhesive bonding, interference couplingor screw coupling methods.

In one embodiment of the shoe 10, 60 with quarter portion according tothe disclosure, the flexing springs 24, 74 are made of a compositematerial with a thermosetting matrix with unidirectional glass fiberswith a ratio between the maximum bending strength expressed in MPa andthe flexural elastic modulus, or Young's modulus, expressed in GPa, bothunderstood along the direction of the main flexing plane, represented bya number that is greater than or equal to 30. Examples of materialscompatible with these characteristics are materials known by theacronyms GC-70-UL, GC-70-ULS and GC-70-ULZ manufactured by GordonComposites.

The quarter portion assembly 32, 82 is adapted to make contact with afront tibial portion 50 and two lateral portions of the leg, which arecontiguous thereto, comprised between the malleolus of the user and theknee, in particular at the minimum anthropometric distance of possibleis comfort, from above the malleolus toward the knee, and adapted toconnect the pair of flexing springs 24 to said front tibial portion 50and two lateral portions of the leg of the user which are contiguous tosaid portion 50.

The quarter portion assembly 32, 82 comprises a rigid support 34, 84 anda resting element 36, 86 which are mutually associated. The quarterportion assembly 32, 82 is associated with the pair of flexing springs24, 74, in particular with the respective rigid terminals 26, 76arranged at their upper ends.

The rigid support 34, 84 has a substantially semicircular shape. Therigid support 34, 84 is characterized by a circular cross-section up tothe point of connection to the rigid upper terminals 26, 76 of theelastic elements 24, 74. In one embodiment of the disclosure, in thisconnection region the rigid support 84 comprises a spherical pivot 97 inorder to allow rotation about one point of the spherical joint 88. Inanother embodiment of the disclosure, in this connection region thecross-section of the rigid support 34 becomes flat in order tofacilitate connection to the coupling elements with hinged coupling 38and allow the rotation about the axis thereof.

The rigid support 34, 84 of the quarter portion assembly 32, 82 is madeof a material with a high modulus and mechanical strength, preferablybut not exclusively made of a material of the metallic type, such as forexample light aluminum alloys or made of composite material such ascarbon fibers in a thermoplastic or thermosetting matrix and also madeof thermoplastic molding resins reinforced with short fibers made ofcarbon, metal or glass.

The rigid support 34, 84 of the quarter portion assembly 32, 82 isarticulated rotatably to the upper end of both of the flexing springs24, 74, in particular to the respective rigid upper terminals 26, 76.

In one embodiment of the shoe 60 with quarter portion according to thedisclosure, the rigid support 84 of the quarter portion assembly 82 isarticulated rotatably to the upper end of both of the flexing springs 74by means of respective spherical joints 88. Each spherical joint 88comprises a is hollow support 96 inside which a spherical pivot 97rotates. The hollow support 96 is comprised within the rigid upperterminal 76 of the flexing spring 74 and is oriented toward the quarterportion assembly 82. The spherical pivot 97 is comprised in the rigidsupport 84 of the quarter portion assembly 82 and is oriented toward theflexing spring 74.

In this case, the rigid support 84 of the quarter portion assembly 32has a rotation axis that is triaxial with respect to the axis oflongitudinal extension of the flexing spring 24.

In another embodiment of the shoe 10 with quarter portion according tothe disclosure, the rigid support 34 of the quarter portion assembly 32is articulated rotatably at the upper end of both of the flexing springs24 by way of respective coupling elements with hinge-like retention 38.

In this case, the rigid support 34 of the quarter portion assembly 32has a rotation axis that is perpendicular with respect to the axis oflongitudinal extension of the flexing spring 24.

The resting element 36, 86 of the quarter portion assembly 32, 82 isconstituted by an ergonomic quarter element, preferably made of plasticmaterial or composite material, which has an internal face and anexternal face that is opposite the internal one. The internal face ofthe resting element 36, 86 is adapted to make contact with the fronttibial portion 50 and two lateral portions of the leg, which arecontiguous to said portion 50, of the user. The outer face of theresting element 36, 86 is adapted to make contact with and rotate aboutthe circular profile of the rigid support 34, 84, with which theexternal face is associate by means of a band-like rotation element 40,90.

In one embodiment of the disclosure, the resting element 36, 86 of thequarter portion assembly 32, 82, in particular its internal face,comprises a padding which is adapted to make contact with the fronttibial portion 50 and two lateral portions of the leg, which arecontiguous to said portion 50, of the user, in a comfortable andergonomic manner. This padding is preferably is made of materialcomprised within expanded resins. For example, the padding can beprovided by means of material commercially known as Poron®, manufacturedby the Rogers Corporation.

In one embodiment of the disclosure, the resting element 36, 86 of thequarter portion assembly 32, 82 is associated with the rigid support 34,84 of the quarter portion assembly 32, 82 by means of a band-likerotation element 40, 90 connected thereto, shaped so that the restingelement 36,86 can rotate about the circular profile of the rigid support34, 84, remaining in any case associated therewith.

In this manner, with particular reference to FIGS. 3 and 4, it isunderstood that the shortening of the elastic elements 24 during theirflexing can change the angle of incidence between the tangent of theirdeformed shape (α, α1, α2) and the rigid support 34, which by being ableto rotate about the resting element 36 through the band-like rotationelement 40, does not allow said resting element 36 any type of slidingbetween it and the portion that is engaged thereby of the leg of theuser.

The shoe 10, 60 with quarter portion according to the disclosure isconfigured so that the user, by wearing it, induces a deformation of theflexing springs 24, 74, for example for a normal upright posture.

The shoe 10, 60 with quarter portion according to the disclosure istherefore a shoe that is energized by means of the preloading of theflexing springs 24, 74 induced by contact between the tibial portion 50engaged by the quarter portion assembly 32, 82 connected thereto, whichin this manner, for example during the gesture of walking or running,release the energy accumulated by position and weight force, returningit in the automatic opening of the ankle and consequently facilitatingalso the backward rotation of the leg around the knee as well as thehorizontal propulsion in the separation of the metatarsus from theground.

The best but not unique adjustment of this effect is achieved whenaligning maximally the foot with the leg, the quarter portion assembly32, 82 is and in particular the resting element 36, 86, still maintainsa slight contact with the leg portion of the user, understood, in thiscase, as the front tibial part 50 that is engaged by the quarter portionelement 36, 86.

Advantageously, the embodiment of the shoe 60 with quarter portionaccording to the disclosure comprising the spherical joints 88 and/or inwhich the upper end of the rigid rod-like element 72 comprises acylindrical seat 102 and the lower end of the flexing spring 74comprises an insert 104, does not condition and/or force a preferentialflexing plane of the flexing springs 74 but rather entrains said flexingsprings 74 on a plurality of flexing planes without conditioning itspreferential flexing plane.

These flexing planes are determined and comprised by the possible anglesof rotation determined by the movement of the insert 104 of the flexingspring 74 in the cylindrical seat 102 of the rigid rod-like element 72and by the possible rotation angles determined by the movement of thespherical joints 88.

In this manner one obtains a portal the flexing of which, while alwaysrespecting the preferential flexing plane of the flexing springs 74(therefore without ever inducing therein torsional tensions or tensionswhich are in any case harmful for their operation and lifespan), can beoriented in a larger angular field and consequently it is more compliantwith the natural angular mobility between the foot and the leg alongtheir rotational geometries around the malleolus.

Advantageously, for a better distribution of the elastic mechanicalenergy, the shoe 10, 60 with quarter portion, in particular thecorresponding assembly comprising the upper 14, 64, the sole 16, 66 andthe midsole 16A, 66A, must have a flexural rigidity I*E, in the regionof the natural joint of the foot related to the metatarsal arch, equalto twice (there being a pair of flexing springs 24, 74) the rigidity I*Eof a flexing spring 24, 74.

The rigidity I*E of the upper/sole/midsole assembly of the shoe 10, 60with quarter portion can decrease or fade out as one proceeds toward thetip or the toe containment region, while it can increase as one proceedstoward the heel or the heel containment region.

Operation of an embodiment of the shoe with quarter portion according tothe disclosure is described hereinafter.

In the normal perfectly upright posture of the human body, the weightforce is transmitted to the resting regions at the foot, through thecenter of the joint of the knee and of the malleolus, which lie more orless on the same vertical axis.

In this condition, the load of the weight force is distributed on thefoot by means of the resting regions of the metatarsal arch and of theheel, with a distribution that is inversely proportional to theirdistances from the center of the malleolus, which can be generallyapproximated to a value of ⅓ on the metatarsal arch and of ⅔ on theheel.

This type of posture of the human body also does not generally representa state of relaxation of the muscles, since they must control itsbalance by means of small but continuous contractions and extensions.

The state of best muscle relaxation and accordingly of minimum internalenergy consumption occurs when, with respect to a static sittingposture, with the upper portion of the weight force of the human bodythat bears on the ischia of the pelvis, and the one related to the lowerlimbs, resting on the feet, the angle comprised between the lower partof the leg and the resting foot forms an angle of approximately 120°.

Otherwise, during a movement, related to the use of the lower limbs withresting of the weight force through the feet, or even during a step ofimposed posture, with the angle comprised between the foot and the lowerpart of the leg that is greater or smaller than 120°, the distributionof the weight force changes value and in particular for angles comprisedbetween the foot and the lower part of the leg of less than 120° saidforce increases its own value on the metatarsal arch, relieving it fromthe heel, consequently generating the need, for the integrity of themuscle-skeleton-ligament system, as well as for the activation of themuscle contractions related to the movement being considered, for acontraction of the gastrocnemius muscle and of its natural antagonists,such as for example the vastus medialis muscle and the upper quadricepsmuscle or rectus femoris muscle, as well as the tibial muscle and thetendons of the toes that converge therein.

An angular variation between the upper part and the lower part of theleg and between the latter and the foot, caused in general by theimbalance of the center of gravity of the human body in order to performa movement or by a simple posture of less than complete muscle rest, theweight force that passes through the center of rotation of the kneeproduces a rotation torque on the malleolus that must be contrasted byreaction upon the resting of the metatarsal arch and by thecorresponding torque.

By applying to the human body, in particular to the foot of the user,the shoe 10, 60 with quarter portion according to the disclosure, thesetorques induce, only due to the weight force that imbalances the centerof gravity of the human body, an elastic deformation on the flexingsprings 24, 74, which are thus adapted to accumulate this energy source,and to relieve the contraction of the gastrocnemius muscle and thecontractions of its natural antagonists.

The elastic energy accumulated by the flexing springs 24, 74 duringloading further contributes, as an additional artificial muscleactivated simply by the energy related to the position weight force ofthe compass of the lower limbs, during the typical angular variations ofthe motor or rest states and/or by the imbalance of the center ofgravity of the human body, with an increase of the weight force on themetatarsal arch, to remove part of said energy from the contraction ofthe gastrocnemius muscle and of the contractions of its naturalantagonists, such as for example the vastus medialis muscle and theupper quadriceps muscle or the rectus femoris muscle.

In this manner, the forces involved are redistributed on a much largerportion of the muscles, and in particular on the gluteus, i.e., thelargest motor is muscle of the human body and the less distal one fromthe cardiac pump, which are subject moreover to lower stress, andtherefore to a lower energy demand, increasing considerably the energyefficiency described previously.

In even greater detail, during the step of return or cessation of theload, the energy accumulated in the flexing springs 24, 74, in additionto relieving the contraction tension of the gastrocnemius and of itsantagonists, during the loading step, and removing a good part thereof,is returned to augment and stabilize, with an almost nil energy cost,part of the natural torques, determined by the anterior and posteriormuscles of the lower limbs, for restoring the angles at the knee andmalleolus, which are typical of their pendulum-like motion or of theirposition of minimum energy demand related to the required movement orpostural action.

Not least, by wearing the shoe 10, 60 with quarter portion according tothe disclosure, and in particular by means of the rigidity of the portalrepresented by the two rigid rod-like elements 22, 72 that connect theflexing springs 24, 74 to the rigid support 34, 84, and consequently tothe quarter portion assembly 36, 86, in particular in the regions ofcontact which are lateral to the leg and are contiguous to the restingof the tibia 50, the excessive and damaging internal and externallateral rotations of the ankle, are protected and limited within asafety interval. In this manner, without forcing excessively thenecessary lateral articulation, the state of balance and stability isfacilitated, relieving from excessive tensions themuscle-ligament-skeletal system that is assigned to this task.

In practice it has been found that the disclosure achieves fully theintended aim and advantages. In particular, it has been shown that theshoe with quarter portion thus conceived allows to overcome thequalitative limitations of the prior art, since it allows to accumulateand return energy substantially only of a gravitational nature, in orderto augment and stabilize the muscle-skeletal-ligament system of thehuman body that is subject to the weight force transmitted by thecontact of one or both feet and consequently is the states of motion orrest related to all non-horizontal positions of the human body that aresubject to the same gravitational weight force.

This allows to obtain a considerable energy saving and a consequentincrease in efficiency, understood as the ratio between the mechanicalwork performed and the energy supplied to a system during the states ofmotion or rest of the human body, related to the upright position or inany case with the foot resting, related to a non-horizontal posture.

One advantage of the shoe with quarter portion according to thedisclosure resides in that it is also capable, during a falling step,such as for example in the return step in jumping, of dampingdecelerations caused by the impact of the foot on the surface, relievingthe muscle-skeletal-ligament system of the human body from weight forcesthat are subject to accelerations that exceed static gravity.

Another advantage of the shoe with quarter portion according to thedisclosure resides in that it offers a high level of comfort to the userwho benefits from it by using it, minimizing the difficulties in fit andaccessibility and maximizing, not least due to a very low weight, theresults in terms of metabolic benefit/saving and performance increase.Furthermore, the shoe with quarter portion according to the disclosureallows an optimum distribution of the pressure that is created betweensaid shoe and the leg of the user during use.

A further advantage of the shoe with quarter portion according to thedisclosure resides in that it can be provided by using materials thatare commonly used and production processes which are relatively simpleor in any case not excessively sophisticated.

Another advantage of the shoe with quarter portion according to thedisclosure resides in that it can be used in various fields, states ofmotion and/or steps of walking as well as also for various staticpostures and not limited to a specific field, state of motion and/orstep of walking or posture.

The disclosure thus conceived is susceptible of numerous modificationsis and variations, all of which are within the scope of the appendedclaims. All the details may further be replaced with other technicallyequivalent elements.

In practice, the materials used, so long as they are compatible with thespecific use, as well as the contingent shapes and dimensions, may beany according to the requirements of the state of the art.

To conclude, the scope of the protection of the claims must not belimited by the illustrations or preferred embodiments shown in thedescription by way of example, but rather the claims must comprise allthe characteristics of patentable novelty that reside in the presentdisclosure, including all the characteristics that would be treated asequivalents by the person skilled in the art.

The disclosures in Italian Patent Application no. 102017000047889, fromwhich this application claims priority, are incorporated herein byreference.

1-14. (canceled)
 15. A shoe with a quarter portion, the shoe comprising:an upper, a sole and a midsole, a pair of rigid elements coupled rigidlyto said sole and/or midsole, a pair of longitudinally extended flexingsprings which are deformable and elastic around the axis of themalleolus of a user wearing said shoe and are adapted to accumulate andreturn elastic mechanical energy and are integral with said pair ofrigid elements, and a quarter portion assembly associated with said pairof flexing springs and adapted to contact a front tibial portion andwith two lateral portions of the leg, which are contiguous to saidportion, of said user.
 16. The shoe according to claim 15, wherein saidquarter portion assembly comprises a rigid support and a resting elementwhich are mutually associated, said rigid support being articulated tothe upper end of said pair of flexing springs.
 17. The shoe according toclaim 16, wherein said pair of flexing springs comprises respectiverigid upper terminals arranged at said upper end of said flexingsprings.
 18. The shoe according to claim 16, wherein said rigid supportis articulated to said upper end of said pair of flexing springs byrespective spherical joints, each of said spherical joints comprises ahollow support inside said spherical joint in which a spherical pivotrotates.
 19. The shoe according to claim 18, wherein said hollow supportis comprised in said rigid upper terminal of said flexing spring and isoriented toward said quarter portion assembly; and in that saidspherical pivot is comprised in said rigid support of said quarterportion assembly and is oriented toward said flexing spring.
 20. Theshoe according to claim 16, wherein said rigid support is articulated tosaid upper end of said pair of flexing springs by respective couplingelements with a retention element.
 21. The shoe according to claim 15,wherein an upper end of said rigid element comprises a cylindrical seatand a lower end of said flexing spring comprises an insert, said insertbeing inserted in said cylindrical seat, said insert being lockedlongitudinally in said cylindrical seat by a locking screw engaged insaid insert and a locking washer.
 22. The shoe according to claim 21,wherein said insert is configured to rotate about the longitudinal axisof said cylindrical seat and said flexing spring is configured to rotateabout the longitudinal axis of said rigid element.
 23. The shoeaccording to claim 15, wherein the assembly comprising the upper, thesole and the midsole has a flexural rigidity, in a region of themetatarsal joint, that is proportional to the rigidity of said pair offlexing springs, with respect to their preferential inward flexingplane, said midsole being interposed between said upper and said sole.24. The shoe according to claim 15, wherein said quarter portionassembly is associated but rotatable with respect to the rigid supportaround a rotation element that is connected thereto.
 25. The shoeaccording to claim 15, wherein said pair of rigid elements comprises atleast one adjustment element configured for adjusting an inclination ofsaid pair of rigid elements.
 26. The shoe according to claim 15, whereinsaid pair of flexing springs is constituted by a material with a ratiobetween a maximum bending strength expressed in MPa and a flexuralelastic modulus, or Young's modulus, expressed in GPa, both understoodalong a direction of the main flexing plane, greater than or equal to30.
 27. The shoe according to claim 16, wherein said resting element ofsaid quarter portion assembly comprises a padding which is arranged onthe internal face and is adapted to contact said front tibial portionand with two lateral portions of the leg that are contiguous to saidportion of said user.
 28. The shoe according to claim 15, furtherincludes a closure system.